In a currently known uplink data transmission solution, encoding processing and modulation processing are performed on uplink data that needs to be sent to a network device by a terminal device, to obtain modulation symbols. The network device performs demodulation processing and decoding processing on the received modulation symbols, to obtain the uplink data.
To improve reliability of the solution, in the foregoing process, the terminal device and the network device need to use an encoding scheme and a decoding scheme that correspond to each other.
In an existing manner, an encoding scheme (or a decoding scheme) for uplink transmission is determined by a network device and then notified to a terminal device. That is, when determining to allocate a time-frequency resource for uplink transmission of the terminal device, the network device performs quality measurement on an uplink channel according to a pilot signal from the terminal device, determines, according to a measurement result, an encoding scheme to be used by the terminal device during uplink transmission on the uplink channel, and notifies the terminal device of the encoding scheme.
However, in the existing manner, the terminal device can perform uplink transmission only after obtaining the encoding scheme notified by the network device. This affects flexibility of uplink transmission.
Therefore, a technology is required to improve flexibility of uplink transmission.